In the first incident, a witness called police after spotting a possible impaired driver near the intersection of Queen Street North and Barton Street West at around 8:05 a.m.

When officers arrived at the scene, they saw the vehicle parked at a curb. Police say they saw the driver stumble out of his car and smelled alcohol on his breath.

Officers then arrested the 46-year-old suspect and charged him with impaired driving.

In the second incident, police received a call after a car hit the rear of a motorcycle that was stopped at the intersection of Main Street East and Kensington Avenue at around 8:30 a.m.

According to police, the caller said the driver was behaving strangely. When officers arrived at the scene, they smelled alcohol on the driver’s breath, police say, and took him into custody.

A 43-year-old faces a count of impaired driver and one count of refusing to provide a breath sample.

In the third case, citizens called police about a single-vehicle collision after which the car involved fled the scene. A driver followed the vehicle, and with the help of other citizens, boxed in the car so it could not escape.

Police said the driver was on her cell phone when officers arrived, and that she smelled of alcohol when she got out of the vehicle.

A 35-year-old woman was arrested and now faces impaired driving and failure to remain charges.

In each case, the accused was release on a promise to appear.

Claus Wagner, a spokesperson with the Hamilton Police Service, said police are “always appreciative” of citizens calling in suspected cases of impaired driving.

Between the beginning of January and the end of August, he said, calls from citizens had led to charges in 109 cases of suspected impaired driving, representing just less than half of all impaired driving arrests in Hamilton this year.

When asked if police advise citizens to try to block the car of a suspected impaired driver, he said: “We would never tell people to put themselves in harm’s way.”